At 5.35pm on Sunday, 31 January, police were called to a residential address on Collingwood Road in Uxbridge following reports of a man taken unwell.
Officers and the London Ambulance Service attended. The 60-year-old man was pronounced dead at the scene. His next of kin has been informed and are being supported by specially trained officers. His name is not being released at present.
The death is currently being treated as suspicious. A post-mortem examination held on 1 February was inconclusive and officers await the results of further tests.
At this early stage, no arrests have been made.
While the cause of his death is yet to be confirmed, the circumstances are being investigated by detectives from the West Area Command Unit.
Detectives wish to trace Frank Sonny Redman, 34, of Uxbridge, as he may have vital information. He was known to the deceased.
If you know of his whereabouts, please get in touch.
Anyone with information is urged to call 101 quoting CAD 5451/31JAN.